SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a16124a920796182e9a493ed5570fdf827ed2497c73be8c25fc59e929ba4e7d' 
  AND token = 'TJEMxiz+xtbK+slGYKFiPMZdSzrH8/syXbllDlPjCBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}